Expansible polishing wheel



Jan. 3, 1939. w. KRAUSE 2,142,873

EXPANS IBLE POLI SHING WHEEL Filed Sept. 28, 1937 INVENTOR. W. Kraus'e Patented Jan. 3, 1939 ExrANsmnE rousnmo wnrzsr. William Krause, West Hartford, Conn., assignor Niles-Bement-Pond Company,

Hartford,

Conn, a corporation of New Jersey Application September 28, 1937, Serial No. 166,137

Claims.

This invention relates to polishing wheels and more particularly to an expansible wheel adapted to be axially compressed into a slightly radially expanded form to securely grip a flexible abra- 5 sive band surrounding the wheel.

An object of the present invention is to provide a polishing wheel that may be supported accurately and centrally in position. upon its driving shaft so that the assembled wheel may be rotated at high speeds without substantial vibration.

Another object of the invention is to provide an improved form of central support for the compressible and resilient material on which the abrasive band is mounted, this support comprising a thin cylindrical shell of metal to the outer cylindrical surface of which is molded the rubber or other compressible material, there being end flanges on the driving shaft adapted to contact with the end walls of the expansible material so that the outer diameter of this rubber may be slightly increased'to firmly grip an endless band of abrasive-charged material mounted thereon.

One feature which is of importance is that the flanges are provided with narrow cylindrical portions adapted to slidably contact with the internal surface of the metal shell or sleeve so that at.

all times the resilient and compressible material supporting the abrasive band is centrally sup- In the accompanying drawing annexed hereto v and forming a part of this specification, I have shown the invention embodied in .an expansible polishing wheel of medium diameter and width, but it will be understood that the invention can be otherwise embodied and that the drawing is not to be construed as defining or limiting the scope ofthe invention, the claims appended to this specification being relied upon for that purpose.

The figure of the drawing shows a sectional view taken centrally through one form of the invention.

In the above-mentioned drawing there has been shown but one embodiment of the invention which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Briefly and in its broadest aspect, the invention may include the following principal parts: First, 5 a central driving shaft having mounted thereon two similar flanges the surfaces of which are disposed in opposed relation to each other; second,

a nut on the shaft engaging a threaded-portion thereof so that the flanges may be adjusted to 10 ward and from each other; third, a thin cylindrical shell or tube disposed between the opposed flanges, the internal surface of this sleeve or tube V engaging narrow cylindrical ledges formed intermediately of the diameter of the flanges; fourth, 15 a heavy layer of rubber or other compressible and resilient material preferably molded to the outer surface of the shell or tube and having an outer cylindrical surface, the end walls of this compressible material being bevelled inwardly and 20 engaging corresponding bevelled portions of the flanges.

Referring more in detail to the figure of the drawing, I provide a driving shaft shown at ID with a reduced end portion II, the outer end of 25 this reduced portion being provided with screw threads I 2. Engaging the screw threads is a nut I3, there also preferably being a Washer 14 on the shaft Ii adjacent the nut.

Mounted upon the portion ll of the driving 30 shaft III are flanges i5 similar to each other but disposed upon the driving shaft II) in opposed relation to each other. These flanges have central openings so that they may freely pass over the reduced portion H of the driving shaft I0. 35 Intermediate their width there are provided narrow shelf-like cylindrical portions or ledges l6, and beyond this portion of each flange is an outwardly flared portion I! as clearly indicated in the figure. v

Centrally mounted upon and engaging the cylindrical ledges ii of the flanges I5 is a cylindrical shell l8. This preferably is made of thin metal tubing closely fitting the diameter of the cylindrical portions of the flanges I6. Directly molded 45 to the outer surface of the shell or tubing I8 is a thick wall I9 of compressible and resilient material such'as rubber. This may conveniently be directly molded to the shell or tubing I8, the shell being used directly in the mold within which the 50 rubber is formed. The outer surface of this material is cylindrical and may be directly formed by means of the molding operation or may be subsequently surfaced as may be desired. Surrounding the outer surface of the compressible 5 and resilient material I9 is the abrasive or polishing band which may be of conventional form, that is it is preferably an endless band of flexible material such as fabric, the outer surface of which is charged with a suitable abrasive bonded in any preferred way to the surface of the fabric.

To mount the band in position upon the expansible wheel the nut I3 is adjusted so that the flanges I 5 may be separated as far as possible and so that their flanged portions I! may engage the outer or end walls of the material l9 without material pressure or compression. In this position of the flanges the band 20 is slipped over the outer surface of the material I9 and the nut l3 tightened upon the threaded portion l2 of the shaft portion II. This adjustment of nut 13 forces the flanges l5 toward each other and permits the ends of shell l8 to slide along the cylindrical surfaces I5 of the flanges. Also it forces the flared portions IT of the flanges tightly against the material l9 thus compressing this material laterally and forcing it slightly radially outward. This slight radial expansion of the material l9 serves to very tightly contact the outer periphery of the material ill with the abrasive band 20 and serves to hold this band in driving relation to the wheel.

As the material [9 is mounted directly upon the shell or tube l8 and the tube rests upon cylindrical surfaces l6 concentric with the axis of rotation of the shaft Ill, the assembled parts of the wheel will at all times remain in perfect central and balanced condition. It will further be noted that the flared portions ll of the flanges I5 are widely spaced laterally and radially from the rethereon engaging and supporting the inner surface of said sleeve. V

2. An expansible polishing wheel comprising in combination, a central cylindrical metal sleeve, compressible and resilient material molded to and surrounding the outer surface thereof, a flexible abrasive band surrounding said material, and 0ppositely disposed flanges engaging and compressing the end walls of said material and having surfaces thereon on which the inner surface of said sleeve is centrally supported.

3. An expansible polishing wheel comprising in combination, a driving shaft, a centrally supported cylindrical metal sleeve, compressible and re silient material secured to and surrounding said sleeve, a flexible abrasive band surrounding said material, oppositely disposed flanges on said shaft adapted to engage and compress said material, cylindrical surfaceson said flanges intermediate their width centrally supporting said sleeve, and clamping means on said shaft for tightening said flanges upon said material whereby said band may be secured to and released from said material.

4. An expansible polishing wheel comprising in combination, a driving shaft, a centrally supported cylindrical metal sleeve, compressible and resilient material secured to and surrounding said sleeve, a flexible abrasive band surrounding said material, oppositely disposed flanges on said shaft adapted to engage and compress said material, cylindrical surfaces on said flanges intermediate their width centrally supporting said sleeve, outwardly flared portions on said flanges engaging the end walls of said material, and clamping means on said shaft for tightening said flanges upon said material whereby said band may be secured to and released from said material.

5. An expansible polishing wheel comprising in combination, a driving shaft, a centrally supported cylindrical metal sleeve, compressible and re- 

